clang-tools-extra/modularize/PreprocessorTracker.h

   1 //===- PreprocessorTracker.h - Tracks preprocessor activities -*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===--------------------------------------------------------------------===//
   8 ///
   9 /// \file
  10 /// Macro expansions and preprocessor conditional consistency checker.
  11 ///
  12 //===--------------------------------------------------------------------===//
  13
  14 #ifndef MODULARIZE_PREPROCESSOR_TRACKER_H
  15 #define MODULARIZE_PREPROCESSOR_TRACKER_H
  16
  17 #include "clang/Lex/Preprocessor.h"
  18
  19 namespace Modularize {
  20
  21 /// Preprocessor tracker for modularize.
  22 ///
  23 /// The PreprocessorTracker class defines an API for
  24 /// checking macro expansions and preprocessor conditional expressions
  25 /// in a header file for consistency among one or more compilations of
  26 /// the header in a #include scenario.  This is for helping a user
  27 /// find which macro expansions or conditionals might be problematic with
  28 /// respect to using the headers in the modules scenario, because they
  29 /// evaluate to different values depending on how or where a header
  30 /// is included.
  31 ///
  32 /// The handlePreprocessorEntry function implementation will register
  33 /// a PPCallbacks object in the given Preprocessor object.  The calls to
  34 /// the callbacks will collect information about the macro expansions
  35 /// and preprocessor conditionals encountered, for later analysis and
  36 /// reporting of inconsistencies between runs performed by calls to
  37 /// the reportInconsistentMacros and reportInconsistentConditionals
  38 /// functions respectively.  The handlePreprocessorExit informs the
  39 /// implementation that a preprocessing session is complete, allowing
  40 /// it to do any needed compilation completion activities in the checker.
  41 class PreprocessorTracker {
  42 public:
  43   virtual ~PreprocessorTracker();
  44
  45   // Handle entering a preprocessing session.
  46   // (Called after a Preprocessor object is created, but before preprocessing.)
  47   virtual void handlePreprocessorEntry(clang::Preprocessor &PP,
  48                                        llvm::StringRef RootHeaderFile) = 0;
  49   // Handle exiting a preprocessing session.
  50   // (Called after preprocessing is complete, but before the Preprocessor
  51   // object is destroyed.)
  52   virtual void handlePreprocessorExit() = 0;
  53
  54   // Handle include directive.
  55   // This function is called every time an include directive is seen by the
  56   // preprocessor, for the purpose of later checking for 'extern "" {}' or
  57   // "namespace {}" blocks containing #include directives.
  58   virtual void handleIncludeDirective(llvm::StringRef DirectivePath,
  59                                       int DirectiveLine, int DirectiveColumn,
  60                                       llvm::StringRef TargetPath) = 0;
  61
  62   // Check for include directives within the given source line range.
  63   // Report errors if any found.  Returns true if no include directives
  64   // found in block.
  65   virtual bool checkForIncludesInBlock(clang::Preprocessor &PP,
  66                                        clang::SourceRange BlockSourceRange,
  67                                        const char *BlockIdentifierMessage,
  68                                        llvm::raw_ostream &OS) = 0;
  69
  70   // Report on inconsistent macro instances.
  71   // Returns true if any mismatches.
  72   virtual bool reportInconsistentMacros(llvm::raw_ostream &OS) = 0;
  73
  74   // Report on inconsistent conditional directive instances.
  75   // Returns true if any mismatches.
  76   virtual bool reportInconsistentConditionals(llvm::raw_ostream &OS) = 0;
  77
  78   // Create instance of PreprocessorTracker.
  79   static PreprocessorTracker *create(
  80     llvm::SmallVector<std::string, 32> &Headers,
  81     bool DoBlockCheckHeaderListOnly);
  82 };
  83
  84 } // end namespace Modularize
  85
  86 #endif